The Final Act
by Iliveinapineappleunderthesea
Summary: "Oh Sherlock, you still haven't realised, have you? I know about you. I know what you are. That thing even Big Brother doesn't know? That's how I'm going to ruin you." Omegaverse fic


**AN: So this is written for a prompt which I vaguely remember asked for Reichenbach, but with Sherlock being revealed as an omega rather than a fraud. I can't remember much more about the prompt and I have no idea where to find it so I'm not entirely sure if I'm keeping with what it asked for. But yeah.  
>IMPORTANT WARNING PLEASE NOTE: I have chosen not to use any warnings. Please take this as a warning for absolutely everything because I will NOT be warning you about any potential triggerssqueaks/anything for this story. If there is something you are particularly worried about send me a message and I can tell you whether or not to be concerned**

**Also, I do not own.**

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><p>"You <em>machine<em>," shouted John, "sod this. Sod this. You stay here if you want, on your own." John headed towards the exit, stopping only to open the door and look back at Sherlock.

"Alone is what I have. Alone protects me." _If only that were true, then Sherlock wouldn't have to go through with what was about to happen_.

"No. _Friends_ protect people, Sherlock," said John angrily before deserting the room. _And isn't that just what Sherlock was about to do? Protect the person he cared most about in the world?_ Sherlock glanced towards his phone at the sound of a text alert.

_I'm waiting…_

_JM_

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><p>When Sherlock failed to present by the age of fifteen he stole Mycroft's photo colorimeter (he'd collected any other necessary equipment years ago) and performed a blood test on himself. The Department of Secondary Genders, or DSG, had declared it illegal to test children's secondary genders before they presented, but Sherlock was already over the average presentation age and he intended to know exactly which cards he had been dealt. Knowledge was power, after all.<p>

Going only by personality, everyone assumed Sherlock would be an Alpha, but Sherlock wanted to be absolutely certain. Mycroft was a Beta after all, and younger siblings tended not to have more dominant secondary genders than their older siblings.

Even knowing this, when Sherlock finished the blood test he immediately repeated it. Because the results _were not logical_. When he got the same result a second time, Sherlock steepled his fingers below his chin and took a shaky breath in, as slowly as he could. _Stressful situations activate the nerves connected to the adrenal glands which secrete the adrenaline produced in the medulla thereby increasing the amount of adrenaline in the bloodstream and preparing the body to enact the 'fight or flight' response…_

Sherlock stood and paced the length of his room. Omegas were rare. There was approximately one child born with the gene for every two million born without it. Like Betas, they were capable of forming a bond with an Alpha, although their twice yearly heats allowed this bond to become much stronger; unbreakable without medical assistance.

Omegas were also commonly regarded as the property of their Alphas, automatically becoming owned by the government when they presented, they would be sold to the highest bidder at auction. They were rarely seen outside of their Alpha's residence, and never on their own. If Sherlock wanted to have any say in his future he couldn't present as an Omega.

Sherlock stopped his pacing and immediately went to the drawer where he put all of his chemistry equipment. Creating a suitable suppressant shouldn't be too hard, Sherlock reasoned, it was just that nobody had tried to before, and a combination of chemicals which mimicked the Alpha hormones should be even easier. Sherlock didn't know how long it was going to take or when he was going to present, so he needed to begin experimenting as soon as possible.

Three weeks later Sherlock officially presented as an Alpha, and a month after that he injected his first completed suppressant for omega hormones.

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><p>"Ah. Here we are at last – you and me, Sherlock, and our problem – the<em> final<em> problem." Sherlock could hear _Stayin' Alive_ playing from Moriarty's phone as he stepped out onto the rooftop. "Staying alive! It's so boring, isn't it?" Moriarty's face changed as he said this, and he stopped the music angrily. "It's just… staying," he continues, "All my life I've been searching for distractions, Sherlock. You were the best distraction out there but now I don't even have you. _Because I've beaten you._ And it was so _easy_, Sherlock. You're just like them; the _ordinary_ people." Moriarty sighed. "And it was just _too _easy."

Sherlock started tapping out a rhythm with his fingers. Moriarty looked up at him and smiled.

"You got that then, did you?"

"Of course, binary code, that's why all those assassins tried to save my life." _Not that it's real, but Moriarty doesn't know Sherlock knows that._

"I told all my clients: last one to Sherlock is a sissy."

"Yes, but now that it's up here," said Sherlock, pointing to his head, "I can use it to alter all the records. I can kill Rich Brook and bring back Jim Moriarty." _Let Moriarty think he has the advantage._

"No, no, no, no, no. This is too easy, it's _too easy,_" cried Moriarty as he buried his head in his hands. "I _know_ you're acting, DOOFUS!" Sherlock stepped back as Moriarty shouted the last word into his face. "Did you really think I wouldn't know? I'm disappointed, Sherlock. I don't _care_ about Richard Brook! That deception was never meant to last, no. I knew you'd fall for it, try to be clever! Now, shall we finish the game? One final act. And you're going to be the one to choose." Sherlock narrowed his eyes.

"And what am I going to choose, exactly?" Moriarty shook his head sympathetically.

"Oh Sherlock, you still haven't realised, have you? I _know_ about you. I know what you _are_. That thing even Big Brother doesn't know? That's how I'm going to ruin you." _He' knowsnobodycanknow,it'snotpossible._

"I don't know what you're talking about." Sherlock knows how to act. His voice doesn't falter.

"Don't PRETEND, Sherlock." Moriarty is suddenly up in Sherlock's face, his rage clear. "You are going to call up Scotland Yard and tell them the truth. And then they are going to arrest you and everyone will know what you are. You're _friends_ are going to betray you when they find out, Sherlock, and you're going to have to _live_ with that." _NononoNO. _Sherlock grasped the shirt of Moriarty's suit and shoved him back against the edge of the roof.

"You're insane." Moriarty smiled and let his weight fall backwards, the only thing keeping him from falling was Sherlock's grasp on his shirt.

"You're just getting that now? How about I give you a little extra incentive?" There was no hint of amusement in his next words. "Your friends will _die_ if you don't." For the first time since he stepped onto the roof Sherlock allowed fear to show on his face.

"John."

"Not just John," Moriarty giggled, before pulling himself up to whisper into Sherlock's ear, "everyone."

"Mrs Hudson." Moriarty looked delighted.

"_Everyone._"

"Lestrade."

"Three bullets; three gunmen; three victims. There's no stopping them now. Unless…"

"Unless I turn myself in," finished Sherlock.

"You can have me arrested; you can torture me; you can do anything you like with me; but nothing's gonna prevent them from pulling the trigger. Your only three friends in the world will _die_. Make the choice, Sherlock, either kill your friends or watch them turn against you." Moriarty's smile was euphoric. "I _told_ you I would burn the heart out of you."

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><p>John Watson was <em>not<em> gay.

Sure, he'd fooled around with other Alphas in Afghanistan, but pickings were slim there. It was rare for Betas to enlist, and sex between Alphas was just something that was generally accepted but not talked about. If anything, those experiences had just cemented John's own heterosexuality in his mind. So why could he not stop thinking about his flatmate like an infatuated teenager with his first crush? Sherlock was an Alpha through and through. John would be hard pressed if he ever tried to find an Alpha who was more dominant than Sherlock. But he couldn't deny the attraction there.

That first night in Angelo's John hadn't been trying to hit on Sherlock. He was honestly just trying to make conversation and find out about his new flatmate. But now? If John didn't already know what Sherlock's response would be (_"married to my work"_), he might've risked it. Sure, a relationship with Sherlock would've meant no bond and no chance of children, but John thought it would've been worth it.

But there was no chance of Sherlock ever wanting a relationship with John anyway, so he would be Sherlock's friend instead. If that was the best he could do then John would be happy with that.

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><p>"Go on Sherlock, off you pop. Your ruin is the only thing that's going to call the killers off; I'm certainly not going to do it." Moriarty stopped grinning at the dawning look on Sherlock's face. "What? What is it? <em>What did I miss?<em>"

"'_You're_ not going to do it.' So the killers _can_ be called off, then – there's a recall code or a word or a number. I don't have to do anything... if I've got you." Sherlock finished that with a sing-song voice.

"Oh! You think you can _make_ me stop the order? You think _you_ can make me do that?"

"Yes. So do you."

Moriarty laughed.

"Sherlock, your big brother and all the King's horses couldn't make me do a thing I didn't want to."

Sherlock smirked at that.

"Yes, but I'm not my brother, remember? I am you; prepared to do anything; prepared to _burn_; prepared to do what ordinary people won't do. You want me to shake hands with you in hell? I shall not disappoint you."

"Nah. You _talk_ big. Naaaah. You're ordinary. You're ordinary; you're on the side of the angels."

"Oh, I may be on the side of the angels, but don't think for one second that I am one of them." Moriarty looked like he was actually surprised

"No," he paused, "you're not. You're _me_! _Thank_ you." Moriarty smiled and slowly held out his hand. Sherlock looked at him, and then took his hand briefly. "Sherlock Holmes. Thank you. _Bless_ you. As long as I'm alive, you can save your friends; you've got a way out." Moriarty kept his eyes on Sherlock's and took one step back. "Well, good luck with that," he smiled, leaned back, and then fell.

Sherlock realised what was happening just as he began to fall, and stretched his arm out to grab the man, any part of him, but all he managed was the barest touch of fabric before Moriarty was gone, tumbling down through the air and landing with a sickening thud, the blood pooling quickly around him.

_"No!" Damnitdamnitdamnit Mycroft can't help now he doesn't even know_. Sherlock whirled around and away from the edge, pacing frantically. He doesn't know how long he has before the snipers have been ordered to shoot. Moriarty will have left him enough time to for the police to arrive but that's all he can be guaranteed. _Fuck notgood._ Sherlock stops himself and takes a breath. He knows what he has to do; there really isn't a choice when John's involved. _John who Sherlock could see wanted more than friendship who was willing to be with Sherlock even if he was an Alpha who Sherlock lo-_ No. _Concentrate._ Sherlock needed to act now. He pulled his phone out and speed-dialled Lestrade. It took the Di three rings to pick up.

"Sherlock? You need to get to the Yard _now_, we've got proof you're not a fraud but the bloody Superintendent wants you to-"

"_Lestrade_," Sherlock cuts him off, "I need you to send a police team to Bart's _right now_."

"What? Sure, look what for Sherlock? I've got John on the other line going on because he thinks you've done something stupid and I need to know what's going on." Sherlock pinches the bridge of his nose _John's worried_ and tries to clear his mind.

"Moriarty's dead, and I need-"

"_Dead?_ How did-"

"He jumped off of Bart's. _I need you_ to send a team of police here right now so that they can _arrest me_," Sherlock practically shouted out the end of his sentence, breathing rapidly.

"Shit. Sherlock, Moriarty's insane, you're not going to need to be arrested if his death had something to do with you. Just calm down okay?"

"No, Lestrade, you don't understand, I need you to arrest me because I'm-" Sherlock took another breath, "because I am an unregistered Omega and I have been using illegal suppressants since before I presented." _ Can't take it back now_. There's a pause on the other end of the line.

"Sherlock are you fucking bullshitting me? Because-"

"_Please_, Lestrade. Do this for me." Another pause. Sherlock can tell Lestrade is taking in the fact that Sherlock just _begged_ him to do something.

"Okay, Sherlock. I'll send them over with instructions to arrest an unregistered Omega, but when you get back here you are going to have to explain _everything_, yeah?"

"Yes, _thank_ you," said Sherlock, and hung up, dropping the phone onto the roof. It would be useless to him soon anyway. Best to get down to the pavement before the police arrived; make everything as quick as possible for them.

Sherlock barely noticed the time it took to get down to the ground, but he knew it would have been at least a couple of minutes. He wasn't expecting the police to be arriving as he got there though. Why were they already there? _Moriarty, obvious, not thinking properly._ Sherlock was crowded as he stepped out of the doors, surrounded instantly by uniformed officers. They were speaking to him, saying something, but Sherlock wasn't listening; couldn't hear them over the slam of a cab door and then:

"_Sherlock!_"

_John._

"Let me come through. Let me come through, please. Sherlock, stop it now. What's going on?" And then John was being held back and Sherlock couldn't look at him he _couldn't look_, not now.

"Just stay where you are John, please, just stay where you are."

"What? No, he's my friend, look, he's my friend, _Sherlock_," Sherlock looked up and saw John struggling to break past a couple of the officers.

"I'm sorry." And then Sherlock was being bundled into the back of a van and all he had time to say was "Goodbye, John," before the doors clanged shut and John was left alone at the bottom of a building with nothing but an ambulance and the dead body of Moriarty cooling swiftly on the sidewalk next to him.


End file.
